Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752934AbbGNNqZ (ORCPT ); Tue, 14 Jul 2015 09:46:25 -0400 Received: from mail.kernel.org ([198.145.29.136]:37797 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752585AbbGNNqW (ORCPT ); Tue, 14 Jul 2015 09:46:22 -0400 Date: Tue, 14 Jul 2015 10:46:23 -0300 From: Arnaldo Carvalho de Melo To: Aaro Koskinen Cc: Alexey Brodkin , linux-arch@vger.kernel.org, Vineet Gupta , Aaro Koskinen , Jiri Olsa , Paul Mackerras , Peter Zijlstra , linux-kernel@vger.kernel.org Subject: Re: [PATCH] Revert "perf tools: Allow to specify custom linker command" Message-ID: <20150714134623.GH2885@kernel.org> References: <1436785853-4260-1-git-send-email-abrodkin@synopsys.com> <20150713202406.GB5020@blackmetal.musicnaut.iki.fi> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150713202406.GB5020@blackmetal.musicnaut.iki.fi> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2181 Lines: 52 Em Mon, Jul 13, 2015 at 11:24:06PM +0300, Aaro Koskinen escreveu: > Hi, > > On Mon, Jul 13, 2015 at 02:10:53PM +0300, Alexey Brodkin wrote: > > This reverts commit 5ef7bbb09f7b > > ("perf tools: Allow to specify custom linker command"). > > > > LD is a pre-defined variable in GNU Make. I.e. it is always defined. > > Which means there's no point to check "LD ?= ..." because it will never > > succeed. And so LD will be either that explicitly passed to make like > > this: > > ------->8------- > > make LD=path_to_my_ld ... > > ------->8------- > > or default value, which is host's "ld". > > > > Latter leads to failure of cross-linkage because instead of cross linker > > "$(CROSS_COMPILE)ld" host's "ld" is used. > > > > As for commit which is reverted here: > > [1] Usually for selection of non-default flavour of CPU core/options > > linker flags are used like "-mtune=xxx" or "-mMyCPUType" etc. > > > > [2] Still to implement ability to use "ld" that differs from > > "$(CROSS_COMPILE)ld" one will need to add new makefile variable like > > TARGET_LD and then check if $(TARGET_LD) is not specified on make > > invocation then use "$(CROSS_COMPILE)ld". > > > > But for now to fix cross-building of perf this revert is enough. > > Hmm. You are probably right, my build system always exports LD with > correct linker for cross builds so perhaps that's why I this "worked" > for me when testing. Sorry. So, I think this is an "Acked-by: Aaro Koskinen " for the revert, right? > I guess the correct fix would be [1], i.e. there should be some new > variable to pass flags to ld command. > > Or maybe [2], could we use make "origin" function? If LD is "default", > then use "$(CROSS_COMPILE)ld", otherwise use what the user passed? When you guys get to some conclusion, please submit a new patch, for now I am taking the revert with the (implied) Acked-by Aaro, ok? - Arnaldo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/